Recruitment, activation and proliferation of CD8+ memory T cells in an immunoprivileged site.
The capacity of a memory cytotoxic T lymphocyte (CTL) population to protect against viral infections is well established, but the processes underlying this protection are less well understood. We have used heterotypic intranasal immunization with influenza A/X31 (H3N2) to protect against a subsequent infection with the neurovirulent influenza A/WSN (H1N1) in either the cerebrospinal fluid or the immunoprivileged brain parenchyma. Viral clearance from both sites was associated with a local infiltration and proliferation of A/WSN-specific CD8+ T cells. Infection in the cerebrospinal fluid elicited a proliferative response in the draining lymph nodes, an anti-H1N1 serum antibody response and an increase in the extracerebral A/WSN-specific CTL precursor frequency. In contrast, infection in the brain parenchyma elicited no lymph node proliferative response or serum antibody response and caused a transient decrease in the extracerebral CTL precursor frequency. Thus the memory CTL population protected against an intracerebral viral infection independent of any immune response occurring in systemic lymphoid tissue.
Stevenson
P G
PG
Nuffield Department of Medicine, John Radcliffe Hospital, Headington, Oxford, GB. Philip.Stevenson@stjude.org
Bangham
C R
CR
Hawke
S
S
D000818:Animals; D001921:Brain / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D007156:Immunologic Memory; D009980:Influenza A virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity
D007252:Influenza Vaccines